them in their efforts to return. These people share many problems usually associated with statelessness. They may find themselves stuck in a twilight zone when, for instance, re-entry to a country of origin is refused or when consular authorities prove unwilling or unable to issue travel documentation, after an application for a residence permit in the Netherlands has been denied.10 In such cases, it may be appropriate to ask whether the government concerned indeed considers them nationals. As return can generally only be effected with the cooperation of the country of origin, the return criterion is in line with several of the principal functions of nationality in international law: the right of States to provide their nationals with diplomatic protection and consular assistance abroad, the obligation of States to allow the return of their nationals and the right of nationals to a passport which would allow them to leave any country, including their own and to return to their own country.11 Demonstrated unreturnability thus points to the absence of several, inter-linked functions of an individual’s presumed nationality. 1.3 Demographic and legal methodology 12. The demographic chapter of this report consists of a quantitative and a qualitative analysis. As far as the quantitative section is concerned, the calculation of the number of stateless persons in the world is primarily dependent upon two factors: the way in which statelessness is defined in each State and the practices in the registration process or other identification methodology used. In the Dutch context, the CBS relies on the GBAs, which in turn include as stateless only those who can accurately document their statelessness. This means that the number of people registered as stateless in the GBA is relatively low. By contrast, there are a large number of people registered in the GBAs as being of unknown nationality which may obscure thousands of people not formally recognized as stateless or alternatively who are not returnable. For this reason, both categories will be scrutinized to reveal the individuals behind the numbers. As for the way stateless persons are registered in the Netherlands, this practice was considered sufficiently complex to warrant special attention (see chapter 3.2). It should be noted that whenever CBS statistics conflicted with those of the IND, CBS figures were given precedence. Several interviews with IND personnel and municipal officials were conducted to shed additional light on the limited availability of data and the way stateless persons are registered in the Netherlands. Case law on registration practices will at times be provided to highlight and clarify striking statistical outcomes. 13. For the qualitative part, NGOs and law firms were asked to provide the authors with names and addresses of (potentially) stateless and/or unreturnable persons. Based on these referrals, 24 people were interviewed in 20 different interviews (family members in identical situations were in some cases interviewed together). Their ages ranged from 21 to 60 and seven out of 24 interviewees were female. They were interviewed in six different cities, in NGO offices, cafés and in one case in the interviewee’s home. Additionally, three different aliens’ detention facilities were visited in order to be able to speak to people in custody. All interviews were semi-structured to assure some level of comparability between the different cases presented here. In each case documentary support was sought to back 10 In applying the distinction between stateless persons and unreturnable persons, we follow the UNHCR report “Mapping Statelessness in the United Kingdom”, November 2011. 11  ee Article 12 of the International Covenant on Civil and Political Rights and also UNHCR, “The S Concept of Stateless Persons under International Law”, Summary Conclusions of an Expert Meeting held in Prato, Italy on 27-28 May 2010, available at http://www.unhcr.org/refworld/ docid/4ca1ae002.html. in the Netherlands 7